Elevator installations typically have at least an elevator car and a counterweight, which are arranged in an elevator shaft and can be moved in opposite directions from one another. The elevator car and the counterweight are then held or moved by means of one or more supporting means, e.g., in the form of cables or belts. The supporting means are for the most part connected with the ends thereof to a fixed structure within the elevator shaft, and travel about deflection rollers that are fastened as a part of a support unit to a support structure of the elevator car or the counterweight. The supporting means may be driven by a drive, e.g., in the form of an electric motor. The described arrangement with deflection rollers that are fastened as a part of a support unit to support structures of the car or of the counterweight results in block-and-tackle arrangements so that a force intended to act on the supporting means from the drive can be kept sufficiently low.
Examples of elevator installations and support units used therein are described, inter alia, in WO 2011/012504, CN 203682813, and CN 103787169.